Manufacture of improved zeolite Beta catalyst

ABSTRACT

A catalyst composition which comprises a crystalline metallosilicate having the structure of zeolite Beta, phosphorus, and a matrix that is substantially free of crystalline aluminum phosphate which has improved resistance to steam deactivation and which has higher cracking activity than analogous catalysts prepared without phosphorus. The crystalline metallosilicate may be used in the as-synthesized form or in the calcined form. Also included is the method to produce the catalyst composition and methods for the use of catalysts prepared by the present method in organic conversion processes. Specific embodiments of the invention involve various techniques for preparation of catalysts containing phosphorus and crystalline metallosilicates having the structure of zeolite Beta. Catalysts prepared according to the method of this invention are useful for organic compound, e.g., hydrocarbon compound, conversion processes. Organic compound conversion processes include cracking, hydrocracking, and transalkylation, among others.

FIELD OF THE INVENTION

This invention relates to a catalyst composition comprising acrystalline metallosilicate having the characteristics of zeolite Betawhich has an improved catalytic cracking activity and hydrothermalstability. The method for producing the catalyst involves theincorporation of phosphorus with the crystalline metallosilicate, eitherin the as-synthesized form or in the calcined form. The inventionrelates to a method for preparing the catalyst, the new catalystcomposition, and use of the new catalyst composition in accordanceherewith as a catalyst component for organic compound, e.g., hydrocarboncompound, conversion.

BACKGROUND OF THE INVENTION

It is desirable to increase the resistance of zeolite Beta basedcatalysts to steam, thermal and liquid phase hydrolytic catalyticdeactivation. The benefits afforded by the increased stability ofzeolite Beta based catalysts due to application of this invention couldhave immediate impact in the development of improved fluid crackingcatalysts.

Zeolite Beta and its preparation are taught in U.S. Pat. No. 3,308,069(Re. 28,341). U.S. Pat. No. 4,642,226 teaches a method for synthesizingcrystals having the structure of zeolite Beta from a reaction mixturecomprising dibenzyldimethylammonium ions as directing agent, and thecrystals synthesized thereby. Highly silicious zeolite Beta described ashaving silica-to-alumina ratios within the range of 20-1,000 isdisclosed in U.S. Pat. No. 4,923,690. U.S. Pat. No. 5,164,170 disclosesa method for synthesizing large crystal size zeolite Beta from areaction mixture using a directing agent comprising tetraethylammoniumcompound and including triethanolamine, and the crystals synthesizedthereby. U.S. Pat. No. 5,232,579 discloses a method for synthesis ofZeolite Beta using a chelating agent. Zeolite Beta is characterized by adistinctive X-ray pattern which distinguishes it from other knowncrystalline silicates. The entire contents of the above disclosures areincorporated herein by reference as to description of the zeolite Betastructure and synthesis.

The X-ray diffraction pattern of the crystalline silicate identified aszeolite Beta is shown in U.S. Pat. No. 3,308,069, herein incorporated byreference. It is indicated in U.S. Pat. No. 3,308,069 that appearanceand disappearance of certain X-ray lines can be attributed tocompositional differences in silicon to aluminum ratios in the sodiumform compositions summarized in Table 2 of that reference withinterplanar d-spacing (Angstroms) given in terms of intensity forseveral dried samples of zeolite Beta. Table 3 of U.S. Pat. No.3,308,069 again shows X-ray diffraction lines for zeolite Beta withcertain variations in intensities and line appearance attributed tocation exchange of zeolite Beta. The more significant d-spacing valuesfor exchanged zeolite Beta appear in Table 4 of U.S. Pat. No. 3,308,069and are as follows:

    ______________________________________                                        Interplanar d-Spacing                                                         (Å)                                                                       ______________________________________                                        11.4 ± 0.2                                                                 7.4 ± 0.2                                                                  6.7 ± 0.2                                                                  4.25 ± 0.1                                                                 3.97 ± 0.1                                                                 3.0 ± 0.1                                                                  2.2 ± 0.1                                                                  ______________________________________                                    

U.S. Pat. No. 4,642,226, incorporated by reference herein, disclosescharacteristic X-ray diffraction lines as determined by standardtechniques and as shown in Table I.

                  TABLE I                                                         ______________________________________                                        Interplanar d-Spacing                                                         (Å)         Relative Intensity (I/I.sub.o)                                ______________________________________                                        11.5 ± 0.3   M-S                                                            7.4 ± 0.2   W                                                              6.6 ± 0.15  W                                                             4.15 ± 0.1   W                                                             3.97 ± 0.1   VS                                                             3.0 ± 0.07  W                                                              2.05 ± 0.05 W                                                             ______________________________________                                    

Cracking catalysts for use in petroleum processing generally consist ofa zeolitic component and a matrix. The zeolitic material is generallydispersed in an inorganic oxide-type sol or gel matrix material to whichone or more clays are added. Because of the need for higher octanegasoline, there has been an emphasis on octane-increasing improvementsin cracking catalysts. Octane-enhancing zeolitic fluid crackingcatalysts have been reviewed recently by Scherzer, Catal. Rev. Sci.Eng., 31 (3), 215-354 (1989). The matrix components described in thearticle include natural or modified clays and inorganic oxides such assilica, alumina, silica-alumina, and silica-magnesia. Other inorganicoxides described for matrices are TiO₂, ZrO₂, P₂ O₅, and B₂ O₃.

Cracking catalysts comprising a zeolite and a matrix material containingaluminum phosphate have been described, for example, in U.S. Pat. Nos.4,873,211 and 4,228,036. Such catalysts comprising a zeolite and aninorganic oxide matrix which contains phosphorus-treated aluminaparticles are described in U.S. Pat. Nos. 4,567,152 and 4,584,091 and inEuropean Patent Applications 176,150 and 403,141. The treatment ofzeolite catalysts with phosphoric acid to provide aphosphorus-containing catalyst is described in U.S. Pat. No. 4,839,319and 4,498,975.

In U.S. Pat. No. 4,430,199, tricresyl or ammonium hydrogen phosphate isimpregnated into a cracking catalyst to improve the tolerance towardpoisoning metals. In addition, boron may be added as a passivatingagent.

U.S. Pat. No. 5,110,776 discloses a method for preparing FCC catalystscomprising modifying the zeolite, e.g., ZSM-5, with phosphorus. U.S.Pat. No. 5,126,298 discloses manufacture of an FCC catalyst comprisingzeolite, e.g., ZSM-5, clay, and phosphorus. Phosphorus treatment hasbeen used on faujasite-based cracking catalysts for metals passivation(see U.S. Pat. Nos. 4,970,183 and 4,430,199); reducing coke make (seeU.S. Pat. Nos. 4,567,152; 4,584,091; and 5,082,815); increasing activity(see U.S. Pat. Nos. 4,454,241 and 4,498,975); increasing gasolineselectivity (see U.S. Pat. No. 4,970,183); and increasing steamstability (see U.S. Pat. Nos. 4,765,884 and 4,873,211).

Phosphorus treatment has also been used on zeolite Beta type catalysts(see U.S. Pat. Nos. 5,232,579; 5,231,064; 5,194,412; 5,190,902;5,179,054; 5,126,298; 4,724,066; and 4,605,637).

As mentioned above, it is desirable to increase the resistance ofzeolite Beta based catalysts to steam, thermal, and liquid phasehydrolytic catalytic deactivation. The benefits afforded by applicationof this invention could have immediate impact in the development ofimproved fluid cracking catalysts. Other applications where more stable,phosphorus containing zeolite Beta catalysts with higher alphaactivities could be of use (e.g., NiMo containing hydrocrackingcatalysts) are also contemplated.

SUMMARY OF THE INVENTION

An economical and reproducible method is provided for preparing animproved catalyst composition comprising a crystalline metallosilicatehaving the structure of zeolite Beta, exhibiting valuable catalyticactivity and selectivity and other valuable properties. The methodcomprises combining the appropriate crystalline metallosilicatematerial, e.g., zeolite of the Beta structure; a matrix or bindermaterial, e.g, a source of silica or clay; source of phosphorus; and, ifdesired, a source of alumina to form a mixture or slurry. The methodthen comprises forming catalyst particles from the mixture or slurryproduct.

This invention involves the incorporation of phosphorus during thepreparation of the catalyst composition. In one embodiment, acrystalline metallosilicate having the characteristics of zeolite Betais impregnated with a water soluble source of phosphorus, non-limitingexamples of which are phosphoric acid, ammonium dihydrogen phosphate orammonium metaphosphate. For example, the phosphorus impregnation may bedone using an incipient wetness technique. Subsequently, a matrix orbinder precursor is added to allow the catalyst particle to be formed.Catalyst particles are then formed and dried.

In another embodiment, a water soluble source of phosphorus may first becombined with a matrix or binder that does not contain an acid-solublesource of aluminum (e.g., clay, SiO₂, ZrO₂, among others) and acrystalline metallosilicate having the characteristics of zeolite Beta.An acid-soluble source of aluminum (e.g., pseudoboehmite) can be addedafter the zeolite has been thoroughly mixed with the matrix or binder.Catalyst particles are then formed and dried.

In a third embodiment, zeolite Beta is combined with a matrix containingan acid-soluble source of aluminum (e.g., pseudoboehmite). The mixtureis formed by a conventional method such as spray drying or extrusion. Awater soluble source of phosphorus is then added after calcination ofthe zeolite Beta-matrix combination (e.g., using an incipient wetnesstechnique to add the phosphorus). Catalyst particles are then formed anddried.

The zeolite Beta may be used in this invention either in the"as-synthesized" form (i.e., still containing an organic directingagent) or in the calcined form (i.e., with the organic directing agentremoved).

The catalyst particles may be calcined at a temperature of from about200° C. to about 800° C. for from about 1 minute to about 48 hours. Apreferred calcination procedure in accordance herewith would be toprovide a calcined product catalyst which retains a trace amount ofcarbon residue. Therefore, partial calcination within the aboveconditions, e.g., at lower temperature and/or shorter time, ispreferred.

Zeolite Beta catalysts prepared according to these methods are moreresistant to steam deactivation than analogous catalysts withoutphosphorus.

DETAILED DESCRIPTION OF THE INVENTION

The invention presents a new and useful catalyst composition comprisinga crystalline metallosilicate having the characteristics of zeoliteBeta, phosphorus, and a matrix material, a method for manufacturing thenew catalyst composition, and use of the new catalyst composition inaccordance herewith as a catalyst component for organic compound, e.g.,hydrocarbon compound conversion.

The invention relates to a catalyst composition comprising a crystallinemetallosilicate having the characteristics of zeolite Beta, phosphorus,and a matrix that is substantially free of crystalline aluminumphosphate. One feature of this invention is that the phosphorus isdistributed over the zeolite or the zeolite and the matrix, in otherwords, the phosphorus is not confined to the matrix.

More particularly, this invention relates to three embodiments of theabove method for manufacturing the improved catalyst composition. Oneembodiment for manufacturing the catalyst composition of this inventionis to modify a crystalline metallosilicate having the characteristics ofzeolite Beta by treating the crystalline metallosilicate with aphosphorus containing aqueous solution. For example, the crystallinemetallosilicate may be phosphorus treated using an incipient wetnesstechnique. Any water soluble source of phosphorus, such as phosphoricacid, ammonium dihydrogen phosphate, or ammonium metaphosphate, amongothers, is useful in this invention. Next, the phosphorus modifiedcrystalline metallosilicate is combined with a matrix or binderprecursor. Next, catalyst particles are formed by conventional methods(e.g., spray drying or extruding) from the combination of the phosphorusmodified crystalline metallosilicate and the matrix or binder precursor.If desired, the catalyst particles may be calcined.

In another embodiment, in a first step, a phosphorus containing aqueoussolution is combined with a first matrix or binder precursor that issubstantially free of an acid-soluble source of aluminum (nonlimitingexamples of which include clay, SiO₂, and ZrO₂, among others) and acrystalline metallosilicate having the characteristics of zeolite Beta.Then in a second step, a second matrix or binder precursor comprising anacid-soluble source of aluminum (a nonlimiting example of which ispseudoboehmite) is added to the aqueous mixture after the zeolite isthoroughly mixed with the first matrix or binder precursor. Next, thecatalyst particle is formed by conventional methods from the aqueousmixture. If desired, the catalyst particle may be calcined after eitherthe first or the second step or both.

In a third embodiment, a crystalline metallosilicate having thecharacteristics of zeolite Beta is combined with a matrix precursorcomprising an acid-soluble source of aluminum (a nonlimiting example ofwhich is pseudoboehmite) to produce a mixture. Particles are formed fromthe mixture by conventional means (e.g., spray drying or extruding).Then the formed particles are calcined and the calcined particles aremodified by treating them with a phosphorus containing aqueous solution(e.g., using an incipient wetness treatment method). Next, the aqueousmixture is formed and dried by conventional methods to form catalystparticles. If desired, the catalyst particles may be calcined.

An advantage of the above method for preparation of the catalystcomposition is that the contact between the crystalline metallosilicateand the phosphorus compound is effective to impregnate themetallosilicate with phosphorus without substantially altering thecrystal structure of the metallosilicate. A further advantage of theabove method is that the contact between the phosphorus solution and anyalumina present in the matrix may be minimized.

The catalyst composition may be calcined at a temperature of from about200° C. to about 800° C. for from about 1 minute to about 48 hours. Thecalcined catalyst will have an alpha value of greater than about 50after it has been converted to the active (i.e., hydrogen) form via, forexample, ammonium exchange and calcination. A preferred calcinationprocedure in accordance herewith would be to provide a calcined productcatalyst which retains a trace amount of carbon residue. Therefore,partial calcination within the above conditions, e.g., at lowertemperature and/or shorter time, is preferred.

The crystalline metallosilicate having the characteristics of zeoliteBeta may be used in its "as synthesized" form. In other words, thezeolite may be used while it still contains an organic directing agentand other organic agents used in synthesis of the crystallinemetallosilicate. Alternatively, the crystalline metallosilicate may beused in its calcined (i.e., organic free) form.

The source of phosphorous useful in the present invention comprises aphosphorous containing compound selected from ammonium monohydrogenphosphate, ammonium dihydrogen phosphate, triammonium phosphate,ammonium hypophosphate, ammonium orthophosphate, ammonium dihydrogenorthophosphate, ammonium monohydrogen orthophosphate, ammoniumhypophosphite, ammonium dihydrogen orthophosphite, phosphoric acid andmixtures thereof. More specific examples include phosphoric acid andammonium dihydrogen phosphate.

The present catalytic compositions will catalyze organic conversionreactions such as cracking, hydrocracking, olefin and wax isomerization,aromatic transalkylation and other conversion reactions usinghydrocarbon feeds of varying molecular sizes. The present catalyticcomposition is particularly useful for reactions in which the molecularweight of the feed is reduced to a lower value, i.e., to reactionsinvolving cracking such as cracking or hydrocracking. Therefore,feedstock comprising hydrocarbon compounds is converted to productcomprising hydrocarbon compounds of lower molecular weight than thefeedstock by contacting the feedstock at conversion conditions with acatalyst comprising the present crystalline material. Cracking may beconducted at a temperature of from about 200° C. to about 800° C., apressure of from about atmospheric pressure to about 100 psig andcontact time of from about 0.1 second to about 60 minutes. Hydrocrackingmay be conducted at a temperature of from about 150° C. to about 550°C., a pressure of from about 100 psig to about 3000 psig, and a weighthourly space velocity of from about 0.1 hr⁻ 1 to about 100 hr⁻¹ with ahydrogen/hydrocarbon molar ratio of from about 0.1 to about 100.

The catalytic process can be either fixed bed, moving bed, transferline, or fluidized bed, and the hydrocarbon flow may be eitherconcurrent or countercurrent to the catalyst flow. The process of theinvention is particularly applicable to the Fluid Catalytic Cracking(FCC) or Thermofor Catalytic Cracking (TCC) processes. In both of theseprocesses, the hydrocarbon feed and catalyst are passed through areactor and the catalyst is regenerated. The two processes differsubstantially in the size of the catalyst particles and in theengineering contact and transfer which is at least partially a functionof catalyst size.

The TCC process is a moving bed and the catalyst is in the shape ofpellets or beads having an average particle size of aboutone-sixty-fourth to one-fourth inch. Active, hot catalyst beads progressdownwardly cocurrent with a hydrocarbon charge stock through a crackingreaction zone. The hydrocarbon products are separated from the cokedcatalyst and recovered, and the catalyst is recovered at the lower endof the zone and regenerated.

Typical TCC conversion conditions include an average reactor temperatureof from about 450° C. to about 540° C.; catalyst/oil volume ratio offrom about 2 to about 7; reactor volume hourly space velocity of fromabout 1 to about 5 vol./hr./vol.; and recycle to fresh feed ratio offrom 0 to about 0.5 (volume).

The process of the invention is also applicable to Fluid CatalyticCracking. In fluidized catalytic cracking processes, the catalyst is afine powder of about 10 to 200 microns. This powder is generallysuspended in the feed and propelled upward in a reaction zone. Arelatively heavy hydrocarbon feedstock, e.g., a gas oil, is admixed witha suitable cracking catalyst to provide a fluidized suspension andcracked in an elongated reactor, or riser, at elevated temperatures toprovide a mixture of lighter hydrocarbon products. The gaseous reactionproducts and spent catalyst are discharged from the riser into aseparator, e.g., a cyclone unit, located within the upper section of anenclosed stripping vessel, or stripper, with the reaction products beingconveyed to a product recovery zone and the spent catalyst entering adense catalyst bed within the lower section of the stripper. In order toremove entrained hydrocarbons from the spent catalyst prior to conveyingthe latter to a catalyst regenerator unit, an inert stripping gas, e.g.,steam, is passed through the catalyst bed where it desorbs suchhydrocarbons conveying them to the product recovery zone. Thefluidizable catalyst is continuously circulated between the riser andthe regenerator and serves to transfer heat from the latter to theformer thereby supplying the thermal needs of the cracking reactionwhich is endothermic.

The FCC conversion conditions include a riser top temperature of fromabout 500° C. to about 595° C., specifically from about 510° C. to about565° C., and most specifically from about 515° C. to about 550° C.;catalyst/oil weight ratio of from about 3 to about 12, specifically fromabout 4 to about 11, and most specifically from about 5 to about 10; andcatalyst residence time of from about 0.5 to about 15 seconds,specifically from about 1 to about 10 seconds.

It is generally necessary that the catalysts be resistant to mechanicalattrition, that is, the formation of fines which are small particles,e.g., less than 20 μm. The cycles of cracking and regeneration at highflow rates and temperatures, such as in an FCC process, have a tendencyto break down the catalyst into fines, as compared with an averagediameter of catalyst particles of about 60-100 microns. In an FCCprocess, catalyst particles range from about 10 to about 200 microns,preferably from about 20 to 150 microns. Excessive generation ofcatalyst fines increases the refiner's catalyst costs.

The feedstock, that is, the hydrocarbons to be cracked, may include inwhole or in part, a gas oil (e.g., light, medium, or heavy gas oil)having an initial boiling point above about 204° C., a 50% point of atleast about 260° C., and an end point of at least about 315° C. Thefeedstock may also include deep cut gas oil, vacuum gas oil, thermaloil, residual oil, cycle stock, whole top crude, tar sand oil, shaleoil, synthetic fuel, heavy hydrocarbon fractions derived from thedestructive hydrogenation of coal, tar, pitches, asphalts, hydrotreatedfeedstocks derived from any of the foregoing, and the like. As will berecognized, the distillation of higher boiling petroleum fractions aboveabout 400° C. must be carried out under vacuum in order to avoid thermalcracking. The boiling temperatures utilized herein are expressed interms of convenience of the boiling point corrected to atmosphericpressure. Resids or deeper cut gas oils having an end point of up toabout 700° C., even with high metals contents, can also be cracked usingthe invention.

Because these catalytic compositions have been found to be stable, theiruse as cracking catalysts, e.g., in fluid catalytic cracking processes,with resid feeds will represent an especially favorable mode ofutilization. Still further, they may be used in combination with one ormore other catalyst components such as, for example, cracking catalystscomprising silica-alumina and/or zeolite Y, e.g., USY.

It is conventional to use an additive catalyst with different propertiesalong with a conventional catalyst to form an optional mixed catalystsystem. The catalyst composition of this invention may be combined withother large-pore zeolites, e.g., zeolites X, Y, ultrastable Y (USY),rare earth exchanged Y (REY), and rare earth exchanged ultrastable Y(RE-USY) among others. The catalyst composition of this invention mayalso be combined with shape-selective zeolites, e.g., zeolites ZSM-5,ZSM-11, ZSM-12, and ZSM-22, among others. These large-pore andshape-selective zeolites are referred to herein as molecular sievecatalysts.

Although neither the cracking catalyst nor the additive catalyst need besteamed prior to use in the present process, and, in fact, are typicallynot steamed prior to use herein, they may be steamed at a temperature offrom about 300° C. to about 800° C. for a time of from about 1 to about200 hours in about 5 to about 100% steam.

Either or both the crystalline material and the large-pore orshape-selective material may be composited with another material whichis resistant to the temperatures and other conditions employed in theorganic conversion process of this invention. Such materials includeactive and inactive materials and other synthetic or naturally occurringporous crystalline molecular sieves, such as zeolites, as well asinorganic materials such as clays and/or oxides such as alumina, silicaor silica-alumina. The latter may be either naturally occurring or inthe form of gelatinous precipitates or gels including mixtures of silicaand metal oxides. Use of a material in conjunction with the zeolite,i.e., combined therewith or present during its synthesis, which itselfis catalytically active may change the conversion and/or selectivity ofthe catalyst.

Naturally occurring clays which can be composited with either or bothcatalyst components herein include the montmorillonite and kaolinfamily, which families include the subbentonites, and the kaolinscommonly known as Dixie, McNamee, Georgia, and Florida clays or othersin which the main mineral constituent is halloysite, kaolinite, dickite,nacrite, or anauxite. Such clays can be used in the raw state asoriginally mined or initially subjected to calcination, acid treatmentor chemical modification.

In addition to the foregoing materials, either or both catalystcomponents can be composited with one or more porous matrix materialssuch as silica, alumina, silica-alumina, silica-magnesia,silica-zirconia, silica-thoria, silica-berylia, silica-titania, as wellas ternary oxide compositions such as silica-alumina-thoria,silica-alumina-zirconia, silica-alumina-magnesia,silica-magnesia-zirconia, and the like. It may also be advantageous toprovide at least a part of the foregoing matrix materials in colloidalform so as to facilitate extrusion of the bound catalyst component(s).

The relative proportions of catalyst component(s) and matrix can varywidely with the content of the former ranging from about 1 to about 95percent by weight, and more usually from about 10 to about 70 weightpercent, of the composite. The large-pore or shape-selective crystallinecracking catalyst component and the zeolite Beta component can beindependently composited with the same or different matrix material orboth materials can be incorporated together in the same matrix material.

The amount of zeolite Beta catalyst component which is added to thelarge-pore or shape-selective crystalline cracking catalyst componentcan be fairly small since the presence of even minor quantities ofzeolite Beta in the combination catalyst can result in substantialoctane gains. The exact weight percent of zeolite Beta relative to thetotal quantity of catalyst component may vary from cracking unit tocracking unit depending upon the desired octane number, total gasolineyield required, the nature of the available feedstock and other similarfactors. For many cracking operations, the weight percent of zeoliteBeta relative to the total quantity of catalyst composition can rangefrom about 0.01 to about 50, specifically from about 0.1 to about 25,and more specifically from about 0.5 to about 10.

EXAMPLES

The following examples are presented to illustrate the unique attributesof phosphorus modified zeolite Beta catalysts prepared according to thisinvention.

Catalysts of this invention and comparative catalysts were prepared andtested to determine the alpha value (α) of the catalysts. When alphavalue is examined, it is noted that the alpha value is an approximateindication of the catalytic cracking activity of the catalyst comparedto a standard catalyst and it gives the relative rate constant (rate ofnormal hexane conversion per volume of catalyst per unit time). It isbased on the activity of silica-alumina cracking catalyst taken as analpha of 1 (rate constant is 0.016 sec⁻¹). The alpha test is describedin U.S. Pat. No. 3,354,078; in the Journal of Catalysis, Vol. 4, p 527(1965); Vol. 6, p. 278 (1966); and Vol. 61, p. 395 (1980), eachincorporated herein by reference as to that description. Theexperimental conditions of the test used herein include a constanttemperature of 538° C. and a variable flow rate as described in detailin the Journal of Catalysis, Vol. 61, p. 395. The higher alpha valuescorrespond to a more active catalyst.

EXAMPLE 1

A series of phosphorus modified zeolite Beta catalysts was prepared bycalcining a powdered sample of zeolite Beta, prepared according to themethod of U.S. Pat. 3,308,069, in N₂ for 3 hours at 900° F. followed bycalcination in air for 3 hours at 1,000° F. This powdered catalyst wasthen impregnated with an aqueous ammonium dihydrogen phosphate solutionby incipient wetness to produce phosphorus loadings of 1 wt. %. Theresulting catalyst was then calcined in air at 1,000° F. for 3 or 10hours. The alpha values of the catalysts were measured and are shownbelow:

    ______________________________________                                        Sample  Phosphorus  Calcination                                               Designation                                                                           Content, Wt. %                                                                            Temp, °F.                                                                        Time, Hr                                                                              Alpha                                   ______________________________________                                        Sample A                                                                              0           1,000     3       452                                     Sample B                                                                              1           1,000     3       440                                     Sample C                                                                              1           1,000     10      552                                     ______________________________________                                    

This example shows that the incorporation of phosphorus does not reducethe alpha activity of calcined zeolite Beta catalysts (alpha values of440 and 452 are statistically equivalent within the variability of thetest, ±5%). In fact, for catalysts calcined for an extended period oftime, phosphorus actually improves the alpha activity.

EXAMPLE 2

A series of zeolite Beta catalysts was prepared by extruding theas-synthesized form (i.e., tetraethylammonium cation form) of zeoliteBeta crystal used in Example 1 with pseudoboehmite (LaRoche Versal 250,alpha alumina monohydrate, LaRoche Chemical, Baton Rouge, La.). Theseextrudates were calcined in N₂ for 3 hours at 900° F. followed bycalcination in air for 3 hours at 1,000° F. The extrudates were thenimpregnated with an aqueous ammonium dihydrogen phosphate solution byincipient wetness to produce phosphorus loadings ranging from 2 to 10wt. %. The resulting catalysts were calcined at either 1,000° F. or1,400° F. for 3 hours. The alpha values of these catalysts were measuredand are shown below:

    ______________________________________                                        Sample  Phosphorus    Calcination                                             Designation                                                                           Content, Wt. %                                                                              Temperature, °F.                                                                    Alpha                                      ______________________________________                                        Sample D                                                                              0             1,000        193                                        Sample E                                                                              2             1,000        190                                        Sample F                                                                              5             1,000        190                                        Sample G                                                                              10            1,000        192                                        Sample H                                                                              0             1,400         57                                        Sample I                                                                              2             1,400         66                                        Sample J                                                                              5             1,400         79                                        Sample K                                                                              10            1,400         70                                        ______________________________________                                    

This example shows that the incorporation of phosphorus does not reducethe alpha activity of calcined alumina bound zeolite Beta catalysts. Infact, for the higher temperature calcined catalysts, phosphorus actuallyimproves the alpha activity relative to the phosphorus-free, hightemperature calcined zeolite Beta catalyst.

EXAMPLE 3

A series of phosphorus modified ZSM-5 catalysts was prepared by addingan aqueous solution of ammonium dihydrogen phosphate to a mixture of anas-synthesized (i.e., organic directing agent containing) commerciallyavailable ZSM-5 powder (Mobil Oil Co., Beaumont, Tex., Mobil CrystalNo. 1) and powdered pseudoboehmite (LaRoche Versal 250, alpha aluminamonohydrate) to form an extrudable paste. Ammonium dihydrogen phosphateconcentrations were varied to produce phosphorus loadings ranging from 2to 10 wt. %. The material was extruded to produce 1/16-inch cylinders,dried, and calcined in N₂ for 3 hours at 900° F. followed by calcinationin air for 3 hours at 1,000° F. The resulting catalysts were thencalcined at either 1,000° F. or 1,400° F. for 3 hours. The alpha valuesof these catalysts were measured and are shown below:

    ______________________________________                                        Sample  Phosphorus    Calcination                                             Designation                                                                           Content, Wt. %                                                                              Temperature, °F.                                                                    Alpha                                      ______________________________________                                        Sample L                                                                              0             1,000        327                                        Sample M                                                                              2             1,000        332                                        Sample N                                                                              5             1,000        392                                        Sample O                                                                              10            1,000        331                                        Sample P                                                                              0             1,400        215                                        Sample Q                                                                              2             1,400        244                                        Sample R                                                                              5             1,400         76                                        Sample S                                                                              10            1,400         56                                        ______________________________________                                    

This example shows that the incorporation of phosphorus into a mixtureof pseudoboehmite and ZSM-5 does not affect the alpha activity of theZSM-5 catalyst providing the calcination temperature is low enough(i.e., <1000° F.). However, the phosphorus does reduce the alpha ofZSM-5 catalysts calcined at higher temperatures, particularly forcatalysts containing more than 2 wt. % phosphorus.

EXAMPLE 4

A phosphorus modified catalyst containing the as-synthesized form ofzeolite Beta (i.e., tetraethylammonium cation form) used in Example 1was prepared by first blending kaolin clay (Kaopaque 10S, a Georgiakaolin from Dry Branch Kaolin Co., Dry Branch, Ga.) and a slurry ofzeolite Beta. The slurry of zeolite Beta was prepared by ball-milling(16 hours at 16% solids in a porcelain ball mill) the zeolite Beta andwater, to which 0.6 wt. % of a dispersant was added (Marasperse N-22,Reed-Lignin, Inc., Greenwich, Conn.). To the zeolite and clay slurry,sufficient phosphoric acid was added to produce a phosphorus level of2.4 wt. % on the finished catalyst. A silica-alumina binder was thenadded to the slurry by first adding colloidal silica (Nalco 1034A, NalcoChemical Co., Chicago, Ill.) and then alumina (Condea Pural,pseudoboehmite alumina, SB III, Condea Chemie GMBH, Hamburg, Germany)peptized with formic acid. The resulting slurry was spray dried at aspray dryer (Niro, Columbia, Md.) outlet temperature of 360° F. Thespray dried material was calcined in N₂ for 3 hours at 900° F., thencalcined in air for 3 hours at 1,000° F. The alpha value of thiscatalyst was measured and is shown below:

    ______________________________________                                        Sample  Phosphorus    Calcination                                             Designation                                                                           Content, Wt. %                                                                              Temperature, °F.                                                                    Alpha                                      ______________________________________                                        Sample T                                                                              2.4           1,000        207                                        ______________________________________                                    

EXAMPLE 5

A zeolite Beta catalyst was prepared by the same procedure described inExample 4 except that no phosphorus compound was added. This catalystwas prepared by blending a slurry of the same ball-milled as-synthesizedzeolite Beta used in Example 4 (i.e., tetraethylammonium cation form)with clay (Kaopaque 10S, a Georgia kaolin). The slurry of zeolite Betawas prepared by ball-milling (16 hours at 16% solids) the zeolite Betaand water to which 0.6 wt. % of a dispersant was added (MarasperseN-22). A silica-alumina binder was then added to the slurry by firstadding colloidal silica (Nalco 1034A) and then alumina (Condea Pural,pseudoboehmite alumina, peptized with formic acid). The resulting slurrywas spray dried at an outlet temperature of 360° F. The spray driedmaterial was calcined in N₂ for 3 hours at 900° F., then calcined in airfor 3 hours at 1,000° F. The alpha value of this catalyst was measuredand is shown below:

    ______________________________________                                        Sample  Phosphorus    Calcination                                             Designation                                                                           Content, Wt. %                                                                              Temperature, °F.                                                                    Alpha                                      ______________________________________                                        Sample U                                                                              0             1,000        188                                        ______________________________________                                    

In conjunction with Example 4, this example shows that the incorporationof phosphorus does not reduce, and actually improves the alpha activityof the calcined zeolite Beta catalyst.

EXAMPLE 6

A series of phosphorus modified zeolite Beta catalysts was prepared bycalcining a powdered sample of the same zeolite Beta used in Example 1in N₂ for 3 hours at 950° F. followed by calcining in air for 3 hours at1,000° F. This powdered catalyst was then impregnated with an aqueousammonium dihydrogen phosphate solution by incipient wetness to produce aphosphorus loading of 1 wt. %. The resulting catalyst was then calcinedat 1,000° F. for 3 or 10 hours and treated in 100% steam at 1,025° F. atatmospheric pressure for 2, 5, 10, or 24 hours. The alpha values ofthese steamed catalysts were measured and are shown below:

    ______________________________________                                        Sample   Steaming  Phosphorus  Calcination                                    Designation                                                                            Time, Hrs Content, wt. %                                                                            Time, Hr                                                                              Alpha                                  ______________________________________                                        Sample V  2        0           3       150                                    Sample W  2        1           3       190                                    Sample X  2        1           10      224                                    Sample Y  5        0           3        79                                    Sample Z  5        1           3       121                                    Sample AA                                                                               5        1           10      188                                    Sample BB                                                                              10        0           3        44                                    Sample CC                                                                              10        1           3       139                                    Sample DD                                                                              10        1           10      177                                    Sample EE                                                                              24        0           3        29                                    Sample FF                                                                              24        1           3        80                                    Sample GG                                                                              24        1           10      144                                    ______________________________________                                    

This example shows that the incorporation of phosphorus improves theresistance of zeolite Beta to hydrothermal deactivation. It also showsthat samples that are calcined for longer periods prior to steaming haveenhanced stability.

EXAMPLE 7

Three identical samples of the calcined catalyst of Example 4 weretreated in 100% steam at 1,000° F. at atmospheric pressure for either 2,5, or 10 hours. The alpha values of the resulting steamed catalysts weremeasured and are shown below:

    ______________________________________                                        Sample    Steaming    Phosphorus                                              Designation                                                                             Time, Hrs   Content, wt. %                                                                            Alpha                                       ______________________________________                                        Sample HH 2           2.4         94                                          Sample II 5           2.4         71                                          Sample JJ 10          2.4         80                                          ______________________________________                                    

EXAMPLE 8

Three identical samples of the calcined catalyst of Example 5 weretreated in 100% steam at 1,000° F. at atmospheric pressure for either 2,5, or 10 hours. The alpha values of the resulting steamed catalysts weremeasured and are shown below:

    ______________________________________                                        Sample     Steaming    Phosphorus                                             Designation                                                                              Time, Hrs   Content, wt. %                                                                            Alpha                                      ______________________________________                                        Sample KK  2           0           52                                         Sample LL  5           0           56                                         Sample MM  10          0           45                                         ______________________________________                                    

A comparison of the alpha values presented in Examples 7 and 8 show thatthe incorporation of phosphorus improves the steam stability of thecracking activity of the fluid zeolite Beta catalyst.

EXAMPLE 9

A zeolite Beta catalyst containing (on basis of weight) 25% zeoliteBeta, 45.3% silica, 3.4% alumina, and 26.3% kaolin was prepared inaccordance with the following method.

Two batches of the same zeolite Beta used in Example 1 weighing 538grams (76.78% solids) were each mixed with 2.5 grams of a dispersant(Marasperse N-22) and 714 grams of deionized (DI) water. Each batch wasball-milled in a one-gallon ball mill containing 7.8 lbs of 1/2 inchagate stones. After 16 hours of ball-milling, 813 ml of DI rinse waterwas added to each ball mill. In a separate vessel, 910.3 grams of kaolinclay (Georgia Kaolin Co. Inc., Elizabeth, N.J., 86.51% solids) was mixedwith 4,722 grams of sodium silicate obtained as N-Clear (PQ Corp.,Valley Forge, Pa.) containing nominally 28.8% SiO₂, 8.8% Na₂ O, andmixed with 49.1 pounds of DI water. The resulting slurry wassuccessively neutralized by addition of 440.6 grams of 96.9% sulfuricacid and 6.84 lbs of aluminum sulfate (General Chemicals Co., MorristownN.J.) as a solution containing 106.07 grams of Al₂ O₃. The ball-milledzeolite was added to this slurry. The slurry was dewatered, reslurried,homogenized and spray dried.

The spray dried catalyst was ammonium exchanged with 5 cc of 1N NH₄ NO₃per gram of catalyst, washed with 10 cc of DI water per gram of catalystand dried at 250° F. The resulting catalyst is identified as catalystNN.

EXAMPLE 10

A phosphorus modified zeolite Beta catalyst was prepared by addingphosphoric acid to kaolin clay (Georgia Kaolin Co.) at a pH of 1.4. Aslurry of the same zeolite Beta used in Example 1 was prepared byball-milling (16 hours at 33% solids) the zeolite Beta and deionizedwater to which 0.6 wt. % (dry basis) of a dispersant was added(Marasperse N-22). The zeolite slurry was added to the phosphorustreated clay and the resulting slurry was mixed for 15 minutes. The pHof the resulting slurry was 1.5. The solids content of the slurry wasadjusted to 25 wt. % using deionized water and the slurry was spraydried to yield a catalyst containing about 15 wt. % zeolite Beta in a78.1 wt. % kaolin and 6.9 wt. % P₂ O₅ matrix. The catalyst was calcinedin air for 3 hours at 1,200° F. This catalyst is identified as CatalystOO.

EXAMPLE 11

A control catalyst used in the present study was a rare earth Y typezeolite (REY) catalyst removed from a commercial FCC unit followingoxidative regeneration and is designated Catalyst PP.

EXAMPLE 12

Catalyst NN was steam deactivated at 1,450° F. for 10 hours in 45%steam/55% air at atmospheric pressure. The steamed catalyst isdesignated QQ and was blended with the commercial REY catalyst, CatalystPP, in proportions to yield 3 wt. % zeolite Beta in the resultingcatalyst. The resulting catalyst which contains Beta, REY and issubstantially phosphorus free is designated Catalyst RR.

EXAMPLE 13

Catalyst OO was steam deactivated at 1,450° F. for 10 hours in 45%steam/55% air at atmospheric pressure. The steamed catalyst isdesignated SS and was blended with the commercial REY catalyst, CatalystPP, in proportions to yield 3 wt. % zeolite Beta in the resultingcatalyst. The resulting catalyst which contains Beta, REY and phosphorusis designated Catalyst TT.

Catalysts PP, RR, and TT were tested to determine catalytic performancein a fixed fluidized bed unit at 960° F. to crack a sour heavy gas oilover a range of catalyst/oil ratios. Properties of the sour heavy gasoil are shown in Table II. Results of the testing were interpolated to a65 vol. % conversion level and are shown in Table III.

                  TABLE II                                                        ______________________________________                                        Charge Stock Property                                                                             Sour Heavy Gas Oil                                        ______________________________________                                        Pour point, °F.                                                                            90                                                        CCR, wt. %          0.54                                                      Kinematic viscosity, cs @ 100 C                                                                   8.50                                                      Aniline point, °F.                                                                         170.5                                                     Bromine number      8.7                                                       Carbon, wt. %       85.1                                                      Hydrogen, wt. %     12.1                                                      Sulfur, wt. %       2.4                                                       Nitrogen, wt. %     0.41                                                      Basic nitrogen, ppm 382                                                       Nickel, ppm         0.3                                                       Vanadium, ppm       0.4                                                       Iron, ppm           0.3                                                       Sodium, ppm         1.3                                                       ______________________________________                                    

                  TABLE III                                                       ______________________________________                                        Effect of Beta with Phosphorus on Catalytic Performance                       Yield Shifts at 65 vol. % conversion                                                        Control                                                                              Delta Yields                                             ______________________________________                                        Catalyst        PP       RR        TT                                         Zeolite         REY      Beta/REY  Beta/REY                                   Additive Phosphorus, wt. %                                                                    --       --        3                                          Percent Beta in Blend,                                                                        0%       3         3                                          wt. %                                                                         C.sub.5.sup.+, Gasoline, wt. %                                                                42.1     (1.2)     (5.1)                                      C.sub.4 's, wt. %                                                                             7.9      0.3       3.5                                        C.sub.1 -C.sub.3 's, wt. %                                                                    7.6      0.7       1.5                                        Coke, wt. %     4.7      (0.1)     (0.1)                                      C.sub.3.sup.=, vol. %                                                                         6.6      0.4       2.3                                        C.sub.4.sup.=, vol. %                                                                         6.2      0.3       3.0                                        iC.sub.4, vol. %                                                                              5.2      0.4       2.5                                        RON, C.sub.5.sup.+  Gasoline                                                                  91.0     1.0       2.6                                        ______________________________________                                         () denotes a negative value                                              

While there have been described what are presently believed to betypical embodiments of the invention, those skilled in the art willrealize that changes and modifications may be made thereto withoutdeparting from the spirit of the invention and it is intended to claimall such changes and modifications as fall within the true scope of theinvention.

We claim:
 1. A method for manufacturing a catalyst compositioncomprising:(a) a first step of combining an aqueous solution of aphosphorus containing compound with a first matrix precursor and zeoliteBeta, said first matrix precursor being substantially free of anacid-soluble source of aluminum; (b) a second step of adding a secondmatrix precursor comprising an acid-soluble source of aluminum to theproduct of the first step; and (c) recovering the catalyst compositionby forming and drying catalyst particles from the product of the secondstep.
 2. A method according to claim 1 further comprising calcining theformed catalyst particles.
 3. A method according to claim 1 wherein thefirst matrix precursor comprises kaolin clay.
 4. A method according toclaim 1 wherein the second matrix precursor comprises pseudoboehmitealumina.
 5. A method according to claim 1 wherein at least one of thefirst or the second matrix precursors comprise colloidal silica.
 6. Thecatalyst composition produced by the method of claim
 1. 7. The methodaccording to claim 1 wherein the first matrix precursor is selected fromthe group consisting of a source of silica, clay, a source of zirconia,and combinations thereof and the second matrix precursor furthercomprises a source of silica.
 8. The method according to claim 7 whereinthe second matrix precursor consists of the source of acid-solublealuminum and the source of silica.
 9. The method according to claim 8wherein the first matrix precursor consists of kaolin clay and thesecond matrix precursor consists of pseudoboehmite alumina and colloidalsilica.
 10. The method according to claim 1 wherein the first matrixprecursor comprises clay and the second matrix precursor comprisespseudoboehmite alumina and a source of silica.
 11. The method accordingto claim 10 wherein the source of silica consists of colloidal silica.12. The method according to claim 1 wherein the catalyst compositioncontains about 25 weight percent of the zeolite Beta based upon thedried catalyst composition.
 13. The method according to claim 1 whereinthe catalyst composition contains about 50 weight percent of the zeoliteBeta based upon the dried catalyst composition.
 14. The method accordingto claim 1 wherein the phosphorus containing compound is selected fromthe group consisting of ammonium metaphosphate, ammonium monohydrogenphosphate, ammonium dihydrogen phosphate, triammonium phosphate,ammonium hypophosphate, ammonium orthophosphate, ammonium dihydrogenorthophosphate, ammonium monohydrogen orthophosphate, ammoniumhypophosphite, ammonium dihydrogen orthophosphite, phosphoric acid andmixtures thereof.
 15. A catalyst composition comprising a phosphorusmodified zeolite Beta and a matrix that is substantially free ofcrystalline aluminum phosphate, the catalyst composition being preparedby the steps of:(a) combining an aqueous solution of a phosphoruscontaining compound with a first matrix precursor and zeolite Beta, thefirst matrix precursor being substantially free of an acid-solublesource of aluminum, the first matrix precursor comprising clay; (b)adding a second matrix precursor comprising an acid-soluble source ofaluminum and comprising a source of silica to the product of step (a);and (c) recovering the catalyst composition by forming and dryingcatalyst particles from the product of step (b).
 16. The catalystcomposition of step 15 wherein the clay of step (a) consists of kaolinclay and wherein the acid-soluble source of aluminum of step (b)consists of pseudoboehmite alumina and wherein the source of silica ofstep (b) consists of colloidal silica.